Xtykutl

I have to initialize copyToDay in a when-expression to get the specific day string, but how can I use it any further? I need the right string in a following function, but Android Studio says copyToDay hasn't been initialized.
Here's my code:

    val onCheckListener = View.OnClickListener {

        it as CheckedTextView

        it.isChecked = !it.isChecked



        when(it){

            copyHoursMonday -> copyToDay = R.string.MONDAY

            copyHoursTuesday -> copyToDay = R.string.TUESDAY

            copyHoursWednesday -> copyToDay = R.string.WEDNESDAY

            copyHoursThursday -> copyToDay = R.string.THURSDAY

            copyHoursFriday -> copyToDay = R.string.FRIDAY

            copyHoursSaturday -> copyToDay = R.string.SATURDAY

            copyHoursSunday -> copyToDay = R.string.SUNDAY

            }

            //Here's the error with copyToDay

            saveCopy(initialStartInMinutes, initialEndInMinutes, isHappyHour, d, copyToDay)

        }



    d.copyHoursMonday.setOnClickListener(onCheckListener)

    d.copyHoursTuesday.setOnClickListener(onCheckListener)

    d.copyHoursWednesday.setOnClickListener(onCheckListener)

    d.copyHoursThursday.setOnClickListener(onCheckListener)

    d.copyHoursFriday.setOnClickListener(onCheckListener)

    d.copyHoursSaturday.setOnClickListener(onCheckListener)

    d.copyHoursSunday.setOnClickListener(onCheckListener)

Is there some way to get copyToDay from the when-expression?
Thanks for for the help!

You need an else branch in your when statement. That way the compiler knows that your variable has been initialised in every possible branch.
For example:

      when(it){

        copyHoursMonday -> copyToDay = R.string.MONDAY

        copyHoursTuesday -> copyToDay = R.string.TUESDAY

        copyHoursWednesday -> copyToDay = R.string.WEDNESDAY

        copyHoursThursday -> copyToDay = R.string.THURSDAY

        copyHoursFriday -> copyToDay = R.string.FRIDAY

        copyHoursSaturday -> copyToDay = R.string.SATURDAY

        else -> copyToDay = R.string.SUNDAY

      }

It's a scope issue. The variable might not have been initialized. it is, in this case, the view you're using. Now, before I continue, I want to mention one thing: The compiler doesn't know whether or not you set that click listener for multiple views or not. As a result, the compiler thinks "If this is any other view, it will not be initialized".

What you can do, is adding an else to the when:

else -> return@OnClickListener;

This means, in any other case, it returns. It doesn't execute the code that depends on the value, and it also won't be initialized.

Alternatively, you can assign a different value in the else brach. Either is fine.

Also, you can optimize your when statement. Since you assign the same value on every branch, you can simply do:

val copyToDay = when(it){

    copyHoursMonday -> R.string.MONDAY

    copyHoursTuesday -> R.string.TUESDAY

    copyHoursWednesday -> R.string.WEDNESDAY

    copyHoursThursday -> R.string.THURSDAY

    copyHoursFriday -> R.string.FRIDAY

    copyHoursSaturday -> R.string.SATURDAY

    copyHoursSunday -> R.string.SUNDAY

    else -> return@OnClickListener

}

Use when as an expression:

val copyToDay = when(it){

    copyHoursMonday -> R.string.MONDAY

    copyHoursTuesday -> R.string.TUESDAY

    //...

}

The reason why it is saying its not initialised is because when your code run if it variable is true copyToDay variable will be initialised..but if it is false copyToDay will not be initialised.
Hence you need to cater for the false scenario.The best is to give it a default value just above the when(it){}